class_docstr: Keeps track of a running mean for seen states.
  
  The filter will be used to normalize observations and will be 
  online updated according to the seen observations of all actors.
docstr: Returns a copy of Filter.
docstr_tok: ["Returns","a","copy","of","Filter","."]
code: def copy(self):
      """Returns a copy of Filter."""
      other = MeanStdFilter(self.shape)
      other.sync(self)
      return other
  
imports: import numpy
label_desc: Use image node_id 4 for calling the MeanStdFilter obj's underlying member method code with example usage: obj.copy() and returns: other